Hydraulic motor



(No Motiel.) 4 Sheets-Sheet 1. W. H. MADDOOK.

HYDRAULIC MOTOR. No. 461,082. Patented Oct. 13.1891.

WITNESSES. INVENTOR.

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(No Model.)

W. H. MADDOGK.

HYDRAULIC MOTOR.

No. 461,082. Patented Oct. 13,1891.

NVENTOR.

WITNESSES,

, maul-mm, wAsmnmuN, u. c.

(No Model.) 4 Sheets-Sheet 4. W. H. MADDOGK.

HYDRAULIC MOTOR. No. 461,082. Patented Oct. 13,1891.

WITNESSES. INVENTOR. 71MMM SWM 7/;

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UNITED STATES PATENT OFFICE.

IVILLIAM H. MADDOCK, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE IVHEATLAND IRON COMPANY, OF \VHEATLAND, PENNSYLVANIA.

HYDRAULIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 461,082, dated October 13, 1891.

Application filed September 20, 1890- Serial No. 365,597. (No model.)

To ail whom it may concern: cylinder 2, so as to conform to the area of the Be it known that I, WILLIAM II. MADDOCK, ports 7 and S and to afford a quick supply of Pittsburg, in the county of Allegheny and and exhaust. Thus the cross-sectional area State of Pennsylvania, have invented a new of the cylinder may sixty-three ((33) square andusefulImprovement in Hydraulic Motors, inches and the area of each series of ports of which the following is a full, clear, and twenty-eight (28) square inches. exact description, reference being had to the The ends of the valve-cylinder are open and accompanying drawings, forming part of this communicate with the chamber 13 of the specification, in whichvalve-chest surrounding the valve-cylinder. IO Figure 1 is a vertical sectional view of the A water-passage 14L enters the middle of the motor, showing the cylinders and pistons and valve-cylinder 10, through the walls of the valves, one of the pistons being at its full valve-chest and of said cylinder, and another stroke and the other at the middle of its stroke, passage 15 leads from the chamber 13. The the section being on the line I I of Fig. 2. passages 14 and 15 lead to opposite ends of Fig. 2 is a vertical cross-section on the line II a valve-chamberD, as hereinafter described. II of Fig. 1. Figs. 3 and dare horizontal sec- The parts of the cylinder 2 and valve-chest tions on the lines IIIIII and IV IV of Fig. 1. 9, and the several partitions forming the Fig. 5 is a side elevation of the reversingchambers and ports above described,may be valve. Fig. 6 is an end elevation thereof. cast in a single piece, as shown in Figs. 1, 3, Fig. 7 is asectional elevation thereof, the secand 4. The piston-rod of the cylinder 2 is tion being on the line VII VII of Fig. 0. Figs. connected to the crank 16 on the main shaft 8, 9, and IO are vertical cross-sections on the 17 of the motor, and the valves/rem 18 of the lines VIII VIII, IX IX, and X X, respectvalve 11 is connected to a yoke or eccentricbox 19, which incloses a cam 20 on the main ivel 25 Likesymbols ofreferenceindicatelikeparts shaft. The side straps or bars of said yoke i ach. may fit against the faces on both sides of the In the drawings I show two hydraulic mocam, the periphery of which bears against tors A and B, coupled together with the same the lateral straps or bars at the end of the crank-shaft. Both motors are constructed in yoke. The outline of the cam is shown in 0 the same manner and a description of the Fig. 2. Aconsiderable portion of its circumdetails of one will serve for both. v ference, about one-quarter (i) (the highest 2 is the motor-cylinder, 3 is the piston, and portion,) is formed substantially on the arc lis the piston-rod, which projects through a of a circle whose center is in the axis of the stuffing-box 5 in the cylinder-head 6. At the main shaft, and an opposite portion of equal 3 5 ends of the cylinder are ports 7 and S, which are (the lowest portion) is similarly formed extend around a considerable portion of the in concentric circular outline 011 a shorter racircumference of the cylinders, so as to afford di'us. These portions of the circumference a relatively large area for the admission and of the cam are included between the lines a: exhaust of water. The valve-chest 9 is pref- 0c and 1 y of Fig. 2. Between these circular 4o erably cast integrally with the cylinder, and portions of the cam its outlines converge has an internal valve-cylinder 10, in which is somewhat rapidly in curved lines. The midapiston-valve 11, having heads I) c at the ends, dle of the highest part of the cam is preferand an intermediate stem of contracted crossably set about ninety degrees of arc in adsectional area. Near the ends of the cylinder Vance of the crank. From this construction 10 are rows of lateral ports cl and c, which it follows that during about one-quarter of open respectively into annular passages 12, the revolution of the main shaft the valve communicating, respectively, with the ports 7 will be at its most advanced position, during and 8 at the ends of the cylinder 2. Each of the next quarter-revolution the valve will be these rows of ports is of relatively large area rapidly retracted to its extreme back posias compared with the cross-section area ofthe tion, at which it will remain during the next zoo quarter-revolution, and during the succeeding quarter-revolution it will rapidly advance to its extreme forward position.

Suppose now that water under pressure be admitted to the valve-cylinder through the which it will force down, so as to turn the crank-shaft with the crank and cam in the direction of the arrow '0. The water displaced. from the lower end of the cylinder 2 will escape through the lower chamber 12 and ports 6 to the chamber 13 and thence through the port 15 to the exhaust-passage of the engine. For one-eighth of the revolution of the cam (one-quarter of the downstrokeof the piston) the valve 11 will remain substantially in the position'illustrated, so as to afford free communication between the supply-passage 14 and the ports (1 and between the chamber 13 and the ports (2. At the end of this period, when the piston has traveled three-fourths of its downstroke, the cam begins to draw the valve down very rapidly, and when the piston completes its doWns-troke the valve will be moved to the middle of its downstroke, so that the heads I) and a shall cover the ports at and 6, respectively. Then as the piston begins its upstroke the cam, still moving the valve down, will cause the heads band 0 to pass below their ports, so as to put the ports 6 into communication with the pressure-supply port 14 and the ports d into communication with the exhaust. The valve reaches its most widely-open position when the piston has completed one-quarter of its upstroke. It begins to close when the piston completes three-quarters of its. stroke, and it closes at the end of the stroke of the piston. From this description the-cycle of the successive operations of the engine will be understood. As shown in Fig. 1 and in the figures on the third sheet of the drawings, the two motors are coupled together, their passages 15 being connected by a U-shaped pipe 21 and the passages 14 connected by a similar pipe 22. The parts of both motors are similarly constructed and arranged, and are indicated. by the same reference-figures, distinguished by the prime mark. Their pistons and valverods are connected with the same crank-shaft; but the cylinder -piston and valve of one motor are set one-quarter stroke in advance of the corresponding parts of the other.

I shall now describe the construction and operation of the valve D, by which I can throttle the Water-supply to the motors or reverse the direction of their motion. The valve-chamber 23 is cylindrical in form, and is provided with a piston-valve 24,'having two heads g it, connected by a hollow stem, the bore of which extends through the heads.

- pipe 21.

The pipes 21 and 22 are connected, respect ively, by branches with annular chambers 25 and 26 near the ends of the valve I), with which they communicate through the ports 2 and 7'. An exhaust-passage 27 leads from the middle of the valve-chamber between the valve-heads g h, and a water-supply pipe 28 enters a passage 29 inthevalve-casing,which communicates with the ends of the valve-cylinder through ports is and m. The stem 30 of the valve extends through the head of the L valve-chamber, and may be connected with a lever 31, by which the valve may be moved I lengthwise. The valve is so constructed that the heads g h are separated for a space equal to the distance between the ports 't'j, so that by moving the valve in its chamber it may be set so that the heads shall cover and close these ports, or so that they shall be in either of the two positions on opposite sides of their respective ports. When the valve is set in the position shown in Fig. 2., the pipe 22 is in communication through the ports a with the water-supplypipe 28, while the pipe 21 through the ports j is in communication with the valvechamberbetween the valve-heads and with the exhaust-passage 27. The motive-fluid is thus supplied to the motors through the pipe 22 and ports 14 14, as above described, while the exhaust takes place through the ports 15 15' and If it be desired to reverse the direction of the'motor, the valve 24 is moved to the left in Figs. 2 and 7 sufficiently to cause the heads g and h to pass over the ports qlj to the left sides thereof. This puts the ports jin communication with the water-supply passage 29, and the portst'in communication with the exhaust passage 27, The watersupply then passes to the motors through the pipe 21, ports 15 15, passage 13, while the exhaust takes place through the ports 14 14' and pipe 22. The consequence is that the direction of motion of the motors is reversed, and the action of the pistons and their controlling-valves 11 11, under these conditions, will be understood by the skilled engineer by reference to Fig. 1. The water-supply may be throttled to any desired degree by moving the valve 24, so that its heads 9 h shall partially close the portsi and j and may be cut ofi altogether by setting the valve, so that these heads shall close the ports. As shown in Figs. 2 and 7, these ports are cut diagonally in the valve-chamber, so that they shall be closed gradually when the valve is moved. The purpose of making the valve-stem hollow is to balance the valve and to prevent it from moving lengthwise in its chamber at the ends of the strokes of the pistons, as it would tend to do were its ends closed.

The power required for operating the motor may be applied to the water by suitable pumps, (not shown,) which maybe used either with or without an accumulator.

The advantages of my invention will be appreciated by thoseskilled in the art.

IIO

By employing a motor-valve quick to open and close at the beginning and end of its stroke I secure a motor of great power, capable of running equally well at high and low rates of speed, and of great utility as applied to the driving of the parts of rolling-mill feedtables, cranes, and other mechanism, Where a motive agent capable of developing high power and easy to control is demanded. The construction of the admission and exhaust ports of large area relatively to the area of the cylinder contributes also to this end.

Another important feature of advantage of the apparatus consists in the fact that the two motors are the same in construction and may be cast from the same pattern, so that the cost of manufacture is reduced to a minimum.

Other points of advantage resulting from the construction of the apparatus in the man- \VILLIAM H. MADDOCK.

Witnesses:

THOMAS W. BAKEWELL, W. B. CORWIN. 

